Prelims 2019 · Science and Technology · Question 83
In the context of proposals to the use of hydrogen-enriched CNG (H-CNG) as fuel for buses in public transport, consider the following statements:<br/>1. The main advantage of the use of H-CNG is the elimination of carbon monoxide emissions.<br/>2. H-CNG as fuel reduces carbon dioxide and hydrocarbon emissions.<br/>3. Hydrogen up to one-fifth by volume can be blended with CNG as fuel for buses.<br/>4. H-CNG makes the fuel less expensive than CNG.<br/><br/>Which of the statements given above is/are correct?
Answer
2 and 3 only
1. Incorrect. H-CNG does not eliminate carbon monoxide emissions; it generally reduces CO due to better combustion.
2. Correct. Blending hydrogen with CNG improves combustion and can reduce CO2 and unburnt hydrocarbon emissions.
3. Correct. H-CNG typically involves blending hydrogen with CNG up to about 18–20% by volume for transport use.
4. Incorrect. Hydrogen blending does not make the fuel cheaper than CNG; hydrogen production, storage and blending add cost.
Hence, statements 2 and 3 only are correct.